From 391c82efa14d6db253f42616d970dacbe826b7d5 Mon Sep 17 00:00:00 2001 From: Valentine Barshak Date: Wed, 10 Oct 2012 03:34:56 +0400 Subject: linux: Do not force GZIP initramfs compression Initramfs compression does not make much sense for the architectures that support compressed kernel images because in this case the data would be compressed twice. This will eventually result in a bigger kernel image and time overhead when uncompressing it. The only reason to use compressed initramfs is to reduce memory usage when the kernel prepares rootfs, and both the unpacked filesystem and initramfs.cpio are present in the memory. Buildroot attempts to force GZIP compression for initramfs, however it doesn't always work because initramfs compression mode depends on RAM disk compression supported by the kernel. Thus, CONFIG_INITRAMFS_COMPRESSION_GZIP depends on CONFIG_RD_GZIP. If CONFIG_RD_GZIP is not set, setting GZIP initramfs compression will have no effect. Besides, the kernel also supports other compression methods, like BZIP2, LZMA, XZ and LZO. Forcing the good old GZIP does not really make much sense any more. This removes initramfs compression settings from Buildroot, so that the default value preset in the kernel config is used, which is CONFIG_INITRAMFS_COMPRESSION_NONE. If initramfs compression is still needed, it can be set in the kernel config (using make linux-menuconfig) Signed-off-by: Valentine Barshak Acked-by: Arnout Vandecappelle (Essensium/Mind) Signed-off-by: Peter Korsgaard --- fs/initramfs/Config.in | 4 ++-- linux/linux.mk | 4 +--- 2 files changed, 3 insertions(+), 5 deletions(-) diff --git a/fs/initramfs/Config.in b/fs/initramfs/Config.in index 22066eef9..ac4503051 100644 --- a/fs/initramfs/Config.in +++ b/fs/initramfs/Config.in @@ -9,8 +9,8 @@ config BR2_TARGET_ROOTFS_INITRAMFS A rootfs.cpio file will be generated in the images/ directory. This is the archive that will be included in the kernel image. - The rootfs in the kernel will always be gzip'ed, regardless - of how buildroot's cpio archive is configured. + The default rootfs compression set in the kernel configuration + is used, regardless of how buildroot's cpio archive is configured. Note that enabling initramfs together with another filesystem formats doesn't make sense: you would end up having two diff --git a/linux/linux.mk b/linux/linux.mk index befef1658..dfc948ca5 100644 --- a/linux/linux.mk +++ b/linux/linux.mk @@ -182,9 +182,7 @@ define LINUX_CONFIGURE_CMDS $(call KCONFIG_ENABLE_OPT,CONFIG_BLK_DEV_INITRD,$(@D)/.config) $(call KCONFIG_SET_OPT,CONFIG_INITRAMFS_SOURCE,\"$(BINARIES_DIR)/rootfs.cpio\",$(@D)/.config) $(call KCONFIG_SET_OPT,CONFIG_INITRAMFS_ROOT_UID,0,$(@D)/.config) - $(call KCONFIG_SET_OPT,CONFIG_INITRAMFS_ROOT_GID,0,$(@D)/.config) - $(call KCONFIG_DISABLE_OPT,CONFIG_INITRAMFS_COMPRESSION_NONE,$(@D)/.config) - $(call KCONFIG_ENABLE_OPT,CONFIG_INITRAMFS_COMPRESSION_GZIP,$(@D)/.config)) + $(call KCONFIG_SET_OPT,CONFIG_INITRAMFS_ROOT_GID,0,$(@D)/.config)) $(if $(BR2_ROOTFS_DEVICE_CREATION_STATIC),, $(call KCONFIG_ENABLE_OPT,CONFIG_DEVTMPFS,$(@D)/.config) $(call KCONFIG_ENABLE_OPT,CONFIG_DEVTMPFS_MOUNT,$(@D)/.config)) -- cgit v1.2.3